* [PATCH] crypto: blkcipher: prefer strlcpy to strncpy
@ 2018-05-29 5:44 Nick Desaulniers
2018-05-29 16:34 ` Eric Biggers
0 siblings, 1 reply; 3+ messages in thread
From: Nick Desaulniers @ 2018-05-29 5:44 UTC (permalink / raw)
To: herbert, davem; +Cc: Nick Desaulniers, linux-crypto, linux-kernel
Fixes stringop-truncation warnings from gcc-8.
Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com>
---
crypto/ablkcipher.c | 8 ++++----
crypto/blkcipher.c | 4 ++--
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c
index d880a48..e38867f 100644
--- a/crypto/ablkcipher.c
+++ b/crypto/ablkcipher.c
@@ -370,8 +370,8 @@ static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_blkcipher rblkcipher;
- strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
- strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
+ strlcpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
+ strlcpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
sizeof(rblkcipher.geniv));
rblkcipher.blocksize = alg->cra_blocksize;
@@ -444,8 +444,8 @@ static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_blkcipher rblkcipher;
- strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
- strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
+ strlcpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
+ strlcpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
sizeof(rblkcipher.geniv));
rblkcipher.blocksize = alg->cra_blocksize;
diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
index 01c0d4a..ee88e48 100644
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -509,8 +509,8 @@ static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_blkcipher rblkcipher;
- strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
- strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
+ strlcpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
+ strlcpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
sizeof(rblkcipher.geniv));
rblkcipher.blocksize = alg->cra_blocksize;
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] crypto: blkcipher: prefer strlcpy to strncpy
2018-05-29 5:44 [PATCH] crypto: blkcipher: prefer strlcpy to strncpy Nick Desaulniers
@ 2018-05-29 16:34 ` Eric Biggers
2018-05-30 2:03 ` Nick Desaulniers
0 siblings, 1 reply; 3+ messages in thread
From: Eric Biggers @ 2018-05-29 16:34 UTC (permalink / raw)
To: Nick Desaulniers; +Cc: herbert, davem, linux-crypto, linux-kernel
On Mon, May 28, 2018 at 10:44:43PM -0700, Nick Desaulniers wrote:
> Fixes stringop-truncation warnings from gcc-8.
>
> Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com>
> ---
> crypto/ablkcipher.c | 8 ++++----
> crypto/blkcipher.c | 4 ++--
> 2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c
> index d880a48..e38867f 100644
> --- a/crypto/ablkcipher.c
> +++ b/crypto/ablkcipher.c
> @@ -370,8 +370,8 @@ static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
> {
> struct crypto_report_blkcipher rblkcipher;
>
> - strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
> - strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
> + strlcpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
> + strlcpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
> sizeof(rblkcipher.geniv));
>
> rblkcipher.blocksize = alg->cra_blocksize;
> @@ -444,8 +444,8 @@ static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
> {
> struct crypto_report_blkcipher rblkcipher;
>
> - strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
> - strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
> + strlcpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
> + strlcpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
> sizeof(rblkcipher.geniv));
>
> rblkcipher.blocksize = alg->cra_blocksize;
> diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
> index 01c0d4a..ee88e48 100644
> --- a/crypto/blkcipher.c
> +++ b/crypto/blkcipher.c
> @@ -509,8 +509,8 @@ static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
> {
> struct crypto_report_blkcipher rblkcipher;
>
> - strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
> - strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
> + strlcpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
> + strlcpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
> sizeof(rblkcipher.geniv));
>
> rblkcipher.blocksize = alg->cra_blocksize;
> --
> 2.7.4
>
Hi Nick, this patch is wrong. The 'struct crypto_report_blkcipher' is being
copied to userspace via netlink, so all bytes of it must be initialized.
strncpy() does this but strlcpy() does not.
I noticed that you're sending out some other patches replacing strncpy() with
strlcpy() too. Can you please double check them for this same bug?
Thanks,
- Eric
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] crypto: blkcipher: prefer strlcpy to strncpy
2018-05-29 16:34 ` Eric Biggers
@ 2018-05-30 2:03 ` Nick Desaulniers
0 siblings, 0 replies; 3+ messages in thread
From: Nick Desaulniers @ 2018-05-30 2:03 UTC (permalink / raw)
To: Eric Biggers; +Cc: Herbert Xu, davem, linux-crypto, Linux Kernel Mailing List
On Tue, May 29, 2018 at 9:34 AM, Eric Biggers <ebiggers3@gmail.com> wrote:
> On Mon, May 28, 2018 at 10:44:43PM -0700, Nick Desaulniers wrote:
>> Fixes stringop-truncation warnings from gcc-8.
>>
>> Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com>
>> ---
>> crypto/ablkcipher.c | 8 ++++----
>> crypto/blkcipher.c | 4 ++--
>> 2 files changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c
>> index d880a48..e38867f 100644
>> --- a/crypto/ablkcipher.c
>> +++ b/crypto/ablkcipher.c
>> @@ -370,8 +370,8 @@ static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
>> {
>> struct crypto_report_blkcipher rblkcipher;
>>
>> - strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
>> - strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
>> + strlcpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
>> + strlcpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
>> sizeof(rblkcipher.geniv));
>>
>> rblkcipher.blocksize = alg->cra_blocksize;
>> @@ -444,8 +444,8 @@ static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
>> {
>> struct crypto_report_blkcipher rblkcipher;
>>
>> - strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
>> - strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
>> + strlcpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
>> + strlcpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
>> sizeof(rblkcipher.geniv));
>>
>> rblkcipher.blocksize = alg->cra_blocksize;
>> diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
>> index 01c0d4a..ee88e48 100644
>> --- a/crypto/blkcipher.c
>> +++ b/crypto/blkcipher.c
>> @@ -509,8 +509,8 @@ static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
>> {
>> struct crypto_report_blkcipher rblkcipher;
>>
>> - strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
>> - strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
>> + strlcpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
>> + strlcpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
>> sizeof(rblkcipher.geniv));
>>
>> rblkcipher.blocksize = alg->cra_blocksize;
>> --
>> 2.7.4
>>
>
> Hi Nick, this patch is wrong. The 'struct crypto_report_blkcipher' is being
> copied to userspace via netlink, so all bytes of it must be initialized.
> strncpy() does this but strlcpy() does not.
>
> I noticed that you're sending out some other patches replacing strncpy() with
> strlcpy() too. Can you please double check them for this same bug?
>
> Thanks,
>
> - Eric
Thanks for pointing out this subtlety, I've retracted the other patches.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2018-05-29 5:44 [PATCH] crypto: blkcipher: prefer strlcpy to strncpy Nick Desaulniers
2018-05-29 16:34 ` Eric Biggers
2018-05-30 2:03 ` Nick Desaulniers
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